Study characteristics

Fig 1. PRISMA diagram

PRISMA diagram.
PRISMA diagram.


Note: Unless otherwise noted, the data presented below represents 161 studies (210 or 211 stratified observation entries) in the primary, non-overlapping dataset that asked study participants whether or not the DID seek care for a past diarrheal illness.

We also have information on whether individuals would seek care for a hypothetical diarrheal illness from 27 studies (96 stratified observation entries).

Figure S1. Data coverage by geography

Number of stratified observation entries in the primary dataset at each administrative level by country. Countries with >10 observations displayed as 10.


Figure S2. Data coverage over time

Number of stratified observation entries in the primary dataset within different time periods. Year represents the year sampling was completed. Excludes 6 entries missing study dates.


Table 1. Study observation characteristics

variable value Total Percent
Time care Any care 170 82.1
First source 29 14.0
Prior to current visit 7 3.4
Within 24 h 1 0.5
Self or child Child 136 65.7
Other 57 27.5
Self 14 6.8
Recall time 14-30 days 143 69.1
Not reported 35 16.9
42-365 days 16 7.7
2-7 days 13 6.3
Study population Caregiver 112 54.1
Other resident 58 28.0
Head of household 23 11.1
Caregiver of patient at health facility 9 4.3
Patient at health facility 5 2.4
Outbreak described No 189 91.3
Yes 18 8.7
Mult choice No 178 86.0
Yes 29 14.0
Location desc Rural 82 39.6
Urban 67 32.4
Urban and Rural 50 24.2
Peri-Urban 5 2.4
IDP or Refugee Camp 2 1.0
Urban and Peri-Urban 1 0.5
Income group Lower middle income 96 46.4
Upper middle income 43 20.8
Low income 41 19.8
High income 27 13.0
Case definition Diarrhea 153 73.9
Gastroenteritis or non-Vc etiologies 32 15.5
Severe diarrhea or cholera 22 10.6


Adjusted estimates of care seeking at hospitals or clinics

Our goal here is to estimate the proportion of individuals that seek care when they or their child have diarrhea symptoms in LMICs. Since diarrhea symptoms vary, and some of the categories above had very few observations (e.g., cholera and “other”) we have grouped these into three broad categories of case definitions (below).

  1. Diarrhea (3+ loose stools in past 24 hours OR general/no explicit definition provided)
  2. Cholera (acute watery diarrhea of any severity, including resulting in death) or severe diarrhea (danger signs, dehydration, hospitalization, 1+ week duration, or death)
  3. Gastroenteritis or other etiologies (diarrhea or vomiting, including specific etiologies eg rotavirus or e coli)

We build generalized linear models with a study-level random intercept following the approach of Wiens et al (2023) PLOS Medicine:

  1. Unadjusted

  2. Univariate models adjusted individually for:

    1. Study methodology and population:
      • case definition
      • timing of care seeking
      • regarding self or child
      • recall period
      • multiple choice questions
      • study population
    2. Contextual factors:
      • outbreak
      • urban/rural
  3. Multivatiate model(s) adjusted for factors identified as significant but not confounding/collinear in univariate models.

NB: Here our observations represent data aggregated to study_id, country, and potential covariate stratifications, for a total of 146 unique observations corresponding to 114 studies. For studies with multiple choice questions, we take the maximum sample size and number seeking care for studies where there were multiple categories of “hospital/clinic” as possible answers.

Figure S9. Prior predictive checks

For the primary analysis, we chose priors that matched the distribution of the data. Specifically, we used a Normal(-0.6,1.5) prior on alpha, where the mean of the distribution (-0.67) matches the median of the observation data (0.339) in logit space. The resulting prior predictive distribution has a median of 0.34 and a mean of 0.37.

In sensitivity analyses, we shift the mean of the prior distribution on alpha up or right 20% in probability space (i.e., mean of -0.38 for the normal distribution in logit space, median of 0.41 for the observation data) and down or left 20% (i.e., mean of -0.99 for the normal distribution in logit space, median of 0.27 for the observation data).


Figure S10. Posterior distributions of the proportion of people seeking care


Table S1. Estimated proportion that seek care

Version Proportion (%)
Unadjusted 39.3 (9.2 - 77.2)
Unadjusted - shift prior left 37 (8.1 - 75.6)
Unadjusted - shift prior right 42.7 (10.2 - 80.6)
Unadjusted - would you 71.1 (35.1 - 94.2)


FYI (not in paper): RE meta-anaysis a la ‘meta’

## Number of studies: k = 146
## Number of observations: o = 136822
## Number of events: e = 42388
## 
##                      proportion           95%-CI
## Random effects model     0.3455 [0.2941; 0.4007]
## 
## Quantifying heterogeneity:
##  tau^2 = 2.0548; tau = 1.4335; I^2 = 99.3% [99.2%; 99.3%]; H = 11.56 [11.26; 11.88]
## 
## Test of heterogeneity:
##              Q d.f. p-value
##  Wald 19392.96  145       0
##  LRT  32811.27  145       0
## 
## Details on meta-analytical method:
## - Random intercept logistic regression model
## - Maximum-likelihood estimator for tau^2
## - Logit transformation
## - Continuity correction of 0.5 in studies with zero cell frequencies
##   (only used to calculate individual study results)


Figure 5. Forest plots

The “estimated” results are the study-level props from the model that includes pop_cat and case_cat.

## I2: 99.9875, 99.98791, 99.98833, ; tau2: 0.77052, 0.79662, 0.8252,


Factors associated with variation in care seeking at hospitals or clinics

Table S2. Univariate analyses - did you

Odds of actually seeking care for diarrhea for each indicated variable, not adjusting for any other variables.

Variable Category Odds ratio
case_cat Diarrhea 1 [Reference]
Gastroenteritis or non-Vc etiologies 2.39 (0.76 - 5.72)
Severe diarrhea or cholera 3.06 (1.4 - 5.95) **
location_desc Non-urban 1 [Reference]
Urban 1.15 (0.64 - 1.82)
Urban and non-urban 1.54 (0.72 - 2.87)
mult_choice 0 1 [Reference]
1 1.11 (0.56 - 1.93)
outbreak_desc 0 1 [Reference]
1 3.1 (1.16 - 7.01) **
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 8.28 (2.15 - 21.49) **
Head of household 1.05 (0.51 - 1.93)
Other resident 1.27 (0.68 - 2.18)
recall_time over30_orNA 1 [Reference]
under30 0.36 (0.2 - 0.61) **
self_or_child Child 1 [Reference]
Other 0.88 (0.48 - 1.44)
Self 0.92 (0.24 - 2.34)
time_care Any care 1 [Reference]
First source 0.88 (0.46 - 1.55)
Prior to current visit 1.42 (0.16 - 5.63)


FYI (not in paper): Univariate analyses - would you

Odds of hypothetically seeking care for diarrhea for each indicated variable, not adjusting for any other variables.

Variable Category Odds ratio
case_cat Diarrhea 1 [Reference]
Gastroenteritis or non-Vc etiologies 22.7 (0.78 - 121.45)
Severe diarrhea or cholera 9.52 (1.69 - 29.66) **
location_desc Non-urban 1 [Reference]
Urban 2.33 (0.32 - 8.28)
Urban and non-urban 1.21 (0.15 - 4.35)
mult_choice 0 1 [Reference]
1 6.79 (1.12 - 23.74) **
outbreak_desc 0 1 [Reference]
1 2.11 (0.21 - 8.92)
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 21.57 (0.74 - 120.01)
Head of household 0.81 (0.18 - 2.39)
Other resident 9.84 (1.63 - 32.54) **
recall_time over30_orNA 1 [Reference]
under30 2.54 (0.07 - 14.93)
self_or_child Child 1 [Reference]
Other 0.81 (0.12 - 3.05)
Self 9.06 (1.41 - 30.75) **
time_care Any care 1 [Reference]
First source 2.52 (0.07 - 13.53)
Prior to current visit NA


Table S3. Sub-analyses by age: studies that are either only adults or only children

Odds of seeking care for diarrhea for adults vs. children, not adjusting for any other variables. We have 130 observations total here.

Variable Category Odds ratio
prop_five 0 1 [Reference]
1 1.07 (0.51 - 2.07)


Table S4. Sub-analyses by age: studies with care seeking stratified by age

Odds of seeking care for diarrhea for adults vs. children, not adjusting for any other variables. We have data from 7 studies that report healthcare seeking at a hospital/clinic by age groups under/over five for LMICs.

Variable Category Odds ratio
prop_five 0 1 [Reference]
1 1.75 (0.29 - 6.04)


FYI (not in paper): RE meta-analysis a la ‘meta’ by age

## Number of studies: k = 14
## Number of observations: o = 26954
## Number of events: e = 7955
## 
##                      proportion           95%-CI
## Random effects model     0.3165 [0.1729; 0.5062]
## 
## Quantifying heterogeneity:
##  tau^2 = 2.0926; tau = 1.4466; I^2 = 99.2% [99.0%; 99.3%]; H = 10.96 [9.99; 12.02]
## 
## Test of heterogeneity:
##             Q d.f. p-value
##  Wald 1561.41   13       0
##  LRT  1775.73   13       0
## 
## Results for subgroups (random effects model):
##                 k proportion           95%-CI  tau^2    tau       Q   I^2
## prop_five = 0   7     0.2844 [0.1079; 0.5665] 2.4459 1.5639 1233.24 99.5%
## prop_five = 1   7     0.3461 [0.1583; 0.5984] 1.6565 1.2870  255.83 97.7%
## 
## Test for subgroup differences (random effects model):
##                   Q d.f. p-value
## Between groups 0.13    1  0.7218
## 
## Details on meta-analytical method:
## - Random intercept logistic regression model
## - Maximum-likelihood estimator for tau^2
## - Logit transformation


FYI (not in paper): Meta-regression a la ‘metafor’ by age

Residual heterogeneity (tau2) is the same between groups

## 
## Mixed-Effects Model (k = 14; tau^2 estimator: REML)
## 
## tau^2 (estimated amount of residual heterogeneity):     2.690 (SE = 1.102)
## tau (square root of estimated tau^2 value):             1.640
## I^2 (residual heterogeneity / unaccounted variability): 99.99%
## H^2 (unaccounted variability / sampling variability):   12778.89
## R^2 (amount of heterogeneity accounted for):            0.00%
## 
## Test for Residual Heterogeneity:
## QE(df = 12) = 66652.799, p-val < .001
## 
## Test of Moderators (coefficient 2):
## QM(df = 1) = 0.246, p-val = 0.620
## 
## Model Results:
## 
##            estimate     se    zval   pval   ci.lb  ci.ub    
## intrcpt      -0.889  0.620  -1.433  0.152  -2.105  0.327    
## prop_five     0.436  0.878   0.496  0.620  -1.285  2.157    
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1


Allowing amounts of residual heterogeneity (tau2) to be different between groups

## 
## Multivariate Meta-Analysis Model (k = 14; method: REML)
## 
## Variance Components:
## 
## outer factor: study_id  (nlvls = 7)
## inner factor: prop_five (nlvls = 2)
## 
##            estim   sqrt  k.lvl  fixed  level 
## tau^2.1    2.977  1.726      7     no      0 
## tau^2.2    2.401  1.550      7     no      1 
## 
## Test for Residual Heterogeneity:
## QE(df = 12) = 66652.799, p-val < .001
## 
## Test of Moderators (coefficient 2):
## QM(df = 1) = 0.245, p-val = 0.620
## 
## Model Results:
## 
##            estimate     se    zval   pval   ci.lb  ci.ub    
## intrcpt      -0.889  0.653  -1.362  0.173  -2.168  0.390    
## prop_five     0.435  0.878   0.495  0.620  -1.286  2.156    
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1


Table S5. Tests for potential confounding

In analyses below, the dependent variable is listed in the header.

self_or_child (self/adult vs child)

Variable Category Odds ratio
case_cat Diarrhea 1 [Reference]
Gastroenteritis or non-Vc etiologies 4.38 (0.02 - 34.05)
Severe diarrhea or cholera 0.74 (0.01 - 4.2)
mult_choice 0 1 [Reference]
1 0.38 (0.01 - 1.94)
outbreak_desc 0 1 [Reference]
1 0.55 (0.01 - 3.13)
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 1.96 (0.02 - 12.1)
Head of household 1.97 (0.01 - 12.41)
Other resident 73.54 (9.33 - 282.68) **
recall_time over30_orNA 1 [Reference]
under30 0.2 (0.03 - 0.73) **
time_care Any care 1 [Reference]
First source 0.36 (0.01 - 1.9)
Prior to current visit 2.22 (0.02 - 14.27)


outbreak_desc

Variable Category Odds ratio
case_cat Diarrhea 1 [Reference]
Gastroenteritis or non-Vc etiologies 1.94 (0.02 - 11.69)
Severe diarrhea or cholera 24.38 (4.04 - 88.67) **
mult_choice 0 1 [Reference]
1 1.83 (0.17 - 7.68)
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 1.44 (0.01 - 8.82)
Head of household 5.79 (0.79 - 21.78)
Other resident 1.59 (0.14 - 6.08)
recall_time over30_orNA 1 [Reference]
under30 0.09 (0.01 - 0.26) **
self_or_child Child 1 [Reference]
Other 2.26 (0.34 - 7.82)
Self 1.61 (0.02 - 9.22)
time_care Any care 1 [Reference]
First source 0.49 (0.03 - 1.94)
Prior to current visit 2.23 (0.02 - 14)


case_cat

Severe diarrhea or cholera
Variable Category Odds ratio
mult_choice 0 1 [Reference]
1 1.47 (0.11 - 6.12)
outbreak_desc 0 1 [Reference]
1 25.37 (3.61 - 92.94) **
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 5.49 (0.14 - 29.16)
Head of household 4.77 (0.58 - 18.2)
Other resident 4.56 (0.57 - 16.57)
recall_time over30_orNA 1 [Reference]
under30 0.03 (0.01 - 0.1) **
self_or_child Child 1 [Reference]
Other 4.27 (0.71 - 14.5)
Self 1.37 (0.01 - 8.2)
time_care Any care 1 [Reference]
First source 1.12 (0.13 - 3.86)
Prior to current visit 9.63 (0.19 - 54.96)


Gastroenteritis or non-V cholerae
Variable Category Odds ratio
mult_choice 0 1 [Reference]
1 0.84 (0.05 - 3.78)
outbreak_desc 0 1 [Reference]
1 1.17 (0.01 - 6.88)
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 10.76 (0.26 - 57.17)
Head of household 0.66 (0.01 - 3.76)
Other resident 19.97 (2.96 - 74.9) **
recall_time over30_orNA 1 [Reference]
under30 0.17 (0.02 - 0.58) **
self_or_child Child 1 [Reference]
Other 12.89 (1.92 - 46.55) **
Self 2.19 (0.02 - 14.11)
time_care Any care 1 [Reference]
First source 0.59 (0.04 - 2.38)
Prior to current visit 2.98 (0.02 - 18.84)


Table S6. Sub-analyses

Vc or severe diarrhea

Is there still an effect of being in an outbreak when we subset the data to just case definitions specific to cholera or severe diarrhea (including death)?

Variable Category Odds ratio
outbreak_desc 0 1 [Reference]
1 2.01 (0.37 - 6.38)


Diarrhea

Is there still an effect of recall period when we subset the data to just case definitions for general diarrhea (not severe or resulting in death)?

Variable Category Odds ratio
recall_time over30_orNA 1 [Reference]
under30 0.72 (0.34 - 1.31)


Table 2. Factors associated with variation in care seeking rates

Odds that an individual seeks care for themselves or their child overall or by alternate case definitions, adjusting for study respondent.

Model including study population and case definition
Variable Category Odds ratio
case_cat Diarrhea 1 [Reference]
Gastroenteritis or non-Vc etiologies 2.2 (0.65 - 5.5)
Severe diarrhea or cholera 2.99 (1.32 - 5.83) **
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 6.94 (1.95 - 17.82) **
Head of household 0.95 (0.47 - 1.7)
Other resident 1.01 (0.53 - 1.76)


FYI (not in paper): Factors associated with variation in hypothetical care seeking rates

Odds that an individual hypothetically seeks care for themselves or their child overall or by alternate case definitions, adjusting for study respondent.

Model including study population and case definition
Variable Category Odds ratio
case_cat Diarrhea 1 [Reference]
Gastroenteritis or non-Vc etiologies 14.72 (0.19 - 91.71)
Severe diarrhea or cholera 5.17 (0.59 - 20.53)
pop_cat Caregiver 1 [Reference]
Caregiver of patient at health facility 14.45 (0.2 - 94.48)
Head of household 0.75 (0.15 - 2.19)
Other resident 5.21 (0.52 - 21.5)


Table S7. Stratified estimates of care seeking by category

Stratifications correspond to questions that refer to care seeking for a caregiver.

Version Model Variable Proportion (%)
Main result 1 Unadjusted 39.3 (9.2 - 77.2)
2 Diarrhea 38.6 (8.4 - 77.1)
2 Gastroenteritis or non-Vc etiologies 69.8 (24.3 - 98.9)
2 Severe diarrhea or cholera 79.5 (37.4 - 99.2)
3 Adjusted for methods 38.3 (8.6 - 76.5)
Shift prior left 1 Unadjusted 37 (8.1 - 75.6)
2 Diarrhea 35.7 (7.3 - 74.4)
2 Gastroenteritis or non-Vc etiologies 66.8 (20.6 - 98.8)
2 Severe diarrhea or cholera 76.5 (32.2 - 99.1)
3 Adjusted for methods 35.8 (7.2 - 73.6)
Shift prior right 1 Unadjusted 42.7 (10.2 - 80.6)
2 Diarrhea 41.3 (9.6 - 78.7)
2 Gastroenteritis or non-Vc etiologies 71.8 (26.2 - 98.9)
2 Severe diarrhea or cholera 81.6 (41 - 99.5)
3 Adjusted for methods 41.5 (10 - 79.1)


FYI (not in paper): Sub-grpup analysis a la ‘meta’ by case definition

## Number of studies: k = 146
## Number of observations: o = 136822
## Number of events: e = 42388
## 
##                      proportion           95%-CI
## Random effects model     0.3455 [0.2941; 0.4007]
## 
## Quantifying heterogeneity:
##  tau^2 = 2.0548; tau = 1.4335; I^2 = 99.3% [99.2%; 99.3%]; H = 11.56 [11.26; 11.88]
## 
## Test of heterogeneity:
##              Q d.f. p-value
##  Wald 19392.96  145       0
##  LRT  32811.27  145       0
## 
## Results for subgroups (random effects model):
##                                                  k proportion           95%-CI
## case_cat = Diarrhea                            122     0.3378 [0.2815; 0.3991]
## case_cat = Severe diarrhea or cholera           16     0.3721 [0.2200; 0.5545]
## case_cat = Gastroenteritis or non-Vc etiol ...   8     0.3927 [0.3092; 0.4830]
##                                                 tau^2    tau        Q   I^2
## case_cat = Diarrhea                            2.1470 1.4653 16670.15 99.3%
## case_cat = Severe diarrhea or cholera          2.2102 1.4867  2436.73 99.4%
## case_cat = Gastroenteritis or non-Vc etiol ... 0.2267 0.4762   209.81 96.7%
## 
## Test for subgroup differences (random effects model):
##                   Q d.f. p-value
## Between groups 1.08    2  0.5817
## 
## Details on meta-analytical method:
## - Random intercept logistic regression model
## - Maximum-likelihood estimator for tau^2
## - Logit transformation
## - Continuity correction of 0.5 in studies with zero cell frequencies
##   (only used to calculate individual study results)


FYI (not in paper): Meta-regression a la ‘metafor’ by case definition

To do this with logit(proportion) as outcome, need to drop Cuban study where 100% sought care.

Residual heterogeneity (tau2) is the same between groups

## 
## Mixed-Effects Model (k = 145; tau^2 estimator: REML)
## 
## tau^2 (estimated amount of residual heterogeneity):     1.934 (SE = 0.230)
## tau (square root of estimated tau^2 value):             1.391
## I^2 (residual heterogeneity / unaccounted variability): 99.99%
## H^2 (unaccounted variability / sampling variability):   19626.08
## R^2 (amount of heterogeneity accounted for):            4.54%
## 
## Test for Residual Heterogeneity:
## QE(df = 142) = 7100957.714, p-val < .001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 8.868, p-val = 0.012
## 
## Model Results:
## 
##                                               estimate     se    zval   pval 
## intrcpt                                         -0.796  0.126  -6.318  <.001 
## case_catGastroenteritis or non-Vc etiologies     0.209  0.541   0.387  0.699 
## case_catSevere diarrhea or cholera               1.101  0.370   2.974  0.003 
##                                                ci.lb   ci.ub      
## intrcpt                                       -1.043  -0.549  *** 
## case_catGastroenteritis or non-Vc etiologies  -0.851   1.269      
## case_catSevere diarrhea or cholera             0.376   1.827   ** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1


Allowing amounts of residual heterogeneity (tau2) to be different between groups

## 
## Multivariate Meta-Analysis Model (k = 145; method: REML)
## 
## Variance Components:
## 
## outer factor: study_id (nlvls = 113)
## inner factor: case_cat (nlvls = 3)
## 
##            estim   sqrt  k.lvl  fixed                                 level 
## tau^2.1    2.189  1.480    122     no                              Diarrhea 
## tau^2.2    1.030  1.015      7     no  Gastroenteritis or non-Vc etiologies 
## tau^2.3    2.212  1.487     16     no            Severe diarrhea or cholera 
## 
## Test for Residual Heterogeneity:
## QE(df = 142) = 7100957.714, p-val < .001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 5.173, p-val = 0.075
## 
## Model Results:
## 
##                                               estimate     se    zval   pval 
## intrcpt                                         -0.771  0.150  -5.131  <.001 
## case_catGastroenteritis or non-Vc etiologies     0.184  0.413   0.446  0.656 
## case_catSevere diarrhea or cholera               1.073  0.473   2.267  0.023 
##                                                ci.lb   ci.ub      
## intrcpt                                       -1.066  -0.477  *** 
## case_catGastroenteritis or non-Vc etiologies  -0.625   0.993      
## case_catSevere diarrhea or cholera             0.145   2.000    * 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1